scholarly journals Rayleigh scattering in few-mode optical fibers

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Zhen Wang ◽  
Hao Wu ◽  
Xiaolong Hu ◽  
Ningbo Zhao ◽  
Qi Mo ◽  
...  
Keyword(s):  
Optical Fibers ◽  
Rayleigh Scattering

scholarly journals Distributed Static and Dynamic Strain Measurements in Polymer Optical Fibers by Rayleigh Scattering

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5049
Author(s):  
Agnese Coscetta ◽  
Ester Catalano ◽  
Enis Cerri ◽  
Ricardo Oliveira ◽  
Lucia Bilro ◽  
...  
Keyword(s):  
Optical Fibers ◽  
Time Domain ◽  
Rayleigh Scattering ◽  
Cost Effective ◽  
Time Domain Reflectometry ◽  
Dynamic Strain ◽  
Strain Measurements ◽  
Graded Index ◽  
Optical Time ◽  
Polymer Optical Fibers

We demonstrate the use of a graded-index perfluorinated optical fiber (GI-POF) for distributed static and dynamic strain measurements based on Rayleigh scattering. The system is based on an amplitude-based phase-sensitive Optical Time-Domain Reflectometry (ϕ-OTDR) configuration, operated at the unconventional wavelength of 850 nm. Static strain measurements have been carried out at a spatial resolution of 4 m and for a strain up to 3.5% by exploiting the increase of the backscatter Rayleigh coefficient consequent to the application of a tensile strain, while vibration/acoustic measurements have been demonstrated for a sampling frequency up to 833 Hz by exploiting the vibration-induced changes in the backscatter Rayleigh intensity time-domain traces arising from coherent interference within the pulse. The reported tests demonstrate that polymer optical fibers can be used for cost-effective multiparameter sensing.

scholarly journals Performance Analysis of Scattering-Level Multiplexing (SLMux) in Distributed Fiber-Optic Backscatter Reflectometry Physical Sensors

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2595 ◽  
Author(s):  
Daniele Tosi ◽  
Carlo Molardi ◽  
Wilfried Blanc ◽  
Tiago Paixão ◽  
Paulo Antunes ◽  
...  
Keyword(s):  
Optical Fibers ◽  
Rayleigh Scattering ◽  
Fiber Optic ◽  
Single Fiber ◽  
Distributed Sensor ◽  
The Core ◽  
Physical Sensors ◽  
Core Section ◽  
Boundary Limits ◽  
Multiple Fibers

Optical backscatter reflectometry (OBR) is a method for the interrogation of Rayleigh scattering occurring in each section of an optical fiber, resulting in a single-fiber-distributed sensor with sub-millimeter spatial resolution. The use of high-scattering fibers, doped with MgO-based nanoparticles in the core section, provides a scattering increase which can overcome 40 dB. Using a configuration-labeled Scattering-Level Multiplexing (SLMux), we can arrange a network of high-scattering fibers to perform a simultaneous scan of multiple fiber sections, therefore extending the OBR method from a single fiber to multiple fibers. In this work, we analyze the performance and boundary limits of SLMux, drawing the limits of detection of N-channel SLMux, and evaluating the performance of scattering-enhancement methods in optical fibers.

Absorption losses and thermal diffusivity of optical fibers investigated by photothermal methods: theory and experiments

1983 ◽  
Vol 61 (9) ◽  
pp. 1334-1346 ◽  
Author(s):  
Dominique Chardon ◽  
Serge J. Huard
Keyword(s):  
Thermal Diffusivity ◽  
Absorption Coefficient ◽  
Optical Fibers ◽  
Rayleigh Scattering ◽  
Modulation Frequency ◽  
Threshold Value ◽  
Phase Delay ◽  
Algebraic Expression ◽  
Photothermal Methods ◽  
Scattering Losses

Both the absorption coefficient and the thermal diffusivity of an optical fiber have been measured using photothermal methods: photoacoustics (P.A.) and photothermal deflection (P.D.). The amplitude of the photothermal signal is proportional to the heat density generated in the fiber core. This in turn is proportional to the light absorption coefficient β. Thus, these techniques allow one to separate the absorption and Rayleigh scattering losses. The results obtained by the two methods are in agreement. A threshold value of 10 dB km−1 mW has been determined experimentally. In both cases, the device is calibrated by replacing the fiber with a heated electric wire. Moreover, the heat must diffuse from the core to the gas so that when the light is modulated, a phase delay appears. A study of phase delay versus modulation frequency gives the thermal diffusivity of the fiber. This is required in order to improve fiber sensors.Theoretically, the cylindrical geometry of the sample permits simple calculations. The thermoelastic equations in solids and coupled thermodynamic ones in the gas have been solved without neglecting viscosity effects. Noting that silica is almost unexpansible, an algebraic expression of the signal has been obtained without any assumptions on the gas transformation processes. Finally, the P.A. and P.D. techniques are compared and some extensions are presented.

scholarly journals Gamma irradiation effect on Rayleigh scattering in low water peak single-mode optical fibers

2011 ◽  
Vol 19 (23) ◽  
pp. 23271 ◽  
Author(s):  
Jianxiang Wen ◽  
Gang-Ding Peng ◽  
Wenyun Luo ◽  
Zhongyin Xiao ◽  
Zhenyi Chen ◽  
...  
Keyword(s):  
Gamma Irradiation ◽  
Optical Fibers ◽  
Rayleigh Scattering ◽  
Single Mode ◽  
Irradiation Effect

scholarly journals Comparison among Different Fiber Coatings on the Concrete Shrinkage Test for Distributed Optical Strain Measurements based on Rayleigh Backscattering

2019 ◽  
Author(s):  
Martin Weisbrich ◽  
Klaus Holschemacher ◽  
Thomas Bier
Keyword(s):  
Optical Fibers ◽  
Strain Measurement ◽  
Rayleigh Scattering ◽  
Fiber Optic ◽  
Reference Method ◽  
Shrinkage Strain ◽  
Rayleigh Backscattering ◽  
Advantages And Disadvantages ◽  
Optical Strain ◽  
Fiber Coatings

The fiber optic strain measurement based on Rayleigh scattering has recently become increasingly popular in automotive or mechanical engineering for strain monitoring and in the construction industry in general, especially structural health monitoring. This technology enables the monitoring of strain along the entire fiber length. Several publications have been published, particularly on the applications to the structural component. This article addresses integrating optical fibers of different coatings into the concrete matrix to measure the shrinkage deformations. In this context, three different coating types were investigated regarding their strain transfer. The fibers were integrated into fine-grained concrete prisms, and the shrinkage strain was compared with a precise dial gauge. The analysis shows a high correlation between the reference method and the fiber measurement, especially with the Ormocer coating. The used acrylate coating is also consistent in the middle area of the specimen but requires a certain strain introduction length to indicate the actual strain. The main result of this study is a recommendation for fiber coatings for shrinkage measurement in fine grain concretes using the distributed fiber optic strain measurement. In addition, the advantages and disadvantages of the measurement method are presented.

Method for Predicting Rayleigh Scattering Loss of Silica-Based Optical Fibers

2007 ◽  
Vol 25 (8) ◽  
pp. 2122-2128 ◽  
Author(s):  
Kyozo Tsujikawa ◽  
Katsusuke Tajima ◽  
Kazuyuki Shiraki ◽  
Izumi Sankawa
Keyword(s):  
Optical Fibers ◽  
Rayleigh Scattering ◽  
Scattering Loss

Approach for reducing the Rayleigh scattering loss in optical fibers

2004 ◽  
Vol 95 (4) ◽  
pp. 1733-1735 ◽  
Author(s):  
K. Saito ◽  
M. Yamaguchi ◽  
A. J. Ikushima ◽  
K. Ohsono ◽  
Y. Kurosawa
Keyword(s):  
Optical Fibers ◽  
Rayleigh Scattering ◽  
Scattering Loss

scholarly journals Comparative measurement of Rayleigh scattering in single-mode optical fibers based on an OTDR technique

1988 ◽  
Vol 6 (4) ◽  
pp. 545-551 ◽  
Author(s):  
M.E. Fermann ◽  
S.B. Poole ◽  
D.N. Payne ◽  
F. Martinez
Keyword(s):  
Optical Fibers ◽  
Rayleigh Scattering ◽  
Single Mode ◽  
Comparative Measurement

Noise induced in optical fibers by double Rayleigh scattering of a laser with a 1/f^ν frequency noise

2016 ◽  
Vol 41 (6) ◽  
pp. 1265 ◽  
Author(s):  
Michael Fleyer ◽  
Seth Heerschap ◽  
Geoffrey A. Cranch ◽  
Moshe Horowitz
Keyword(s):  
Optical Fibers ◽  
Rayleigh Scattering ◽  
Frequency Noise
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